The Environment Act 2021 requires a minimum of 10% net gain in biodiversity (secured for a minimum of 30 years). This will be re-considered when the Local Plan is reviewed and may increase. Proposals should maximise opportunities for biodiversity and make a meaningful contribution to nature recovery in line with our Nature Recovery Vision and the Exmoor National Park Management Plan.
Under the statutory framework for Biodiversity Net Gain, every grant of planning permission in England is deemed to have been granted subject to a general biodiversity gain condition to secure the biodiversity gain objective. This objective is to deliver at least a 10% increase in relation to the pre-development biodiversity value of the development granted permission. The general biodiversity gain condition is a pre-commencement condition: once planning permission has been granted, a Biodiversity Gain Plan must be submitted and approved by the planning authority before commencement of the development.
A minimum of 10% BNG (secured for a minimum of 30 years) will be required for all applications, except:
Householder applications
Permitted development
Development impacting an area below a 'de minimis' threshold of 25m2 (5m by 5m) of on-site habitat or 5m of on-site linear habitats (such as hedgerows), where no priority habitat is present
Biodiversity gain sites (where habitats are being enhanced for the purpose of fulfilling the biodiversity gain condition for another development)
Urgent crown development
Development on sites with a redline boundary of 0.2 hectares (total development area) or less unless priority habitats are affected
Temporary planning permissions lasting up to 5 years
BNG also does not apply to retrospective applications
For development which is exempt from 10% BNG requirements, we still require biodiversity enhancements in line with our local plan policy (see Appendix 1).
Every planning application should be submitted with a completed Exmoor Biodiversity Trigger List, Ecological Impact Assessment and survey reports as required. This is now a local list requirement (ENPA Requirements for the Submission of Planning and Other Applications, Dec 2025).
The Natural Environment Record (NER) is Exmoor's repository for biological information, containing wildlife data collected from throughout the National Park. The NER includes an interactive map which can help with finding information on Exmoor's wildlife habitats, species and designations. For detailed data searches please contact the local records centre (Somerset Environmental Records Centre or Devon Biodiversity Records Centre).